摘要
高动态下长周期直扩信号由于大的多普勒频移影响捕获时间极长,提出了一种高动态直扩系统中长周期伪码信号的快速捕获方法,该方法利用复数FFT与窗函数卷积以及相干累加来实现,适合于多速率数据调制以及大频偏下低信噪比直扩信号的接收,捕获时间短,且易于硬件实现。实验结果表明,该方法在多普勒范围为-250^+250kHz、低信噪比条件下快速实现捕获。
The acquisition time of long periodic signal becomes more longer in high dynamic state.A fast acquisition scheme of long periodic signal for direct sequence spread spectrum system in high dynamic state is developed in this paper,which is especially suitable for the simultaneous presence of various rate data modulation and wide Doppler shift range at low signal-to-noise ratio.The technique is based on FFT,coherent integration and regular window,which can reduce the acquisition time largely and can be implemented with less hardware cost.Some computer simulation results are given,which show that the technique can achieve fast acquisition when Doppler shift ranges from-250kHz to＋250kHz and the signal to noise ratio is low.
出处
《信息技术》
2010年第8期32-35,共4页
Information Technology
关键词
扩频通信
多普勒频移
FFT
窗函数
spread spectrum communication
Doppler shift
FFT
regular window
